Pressure Converter
Convert pressure between PSI (tyre pressure), bar, kilopascals, atmospheres, and mmHg.
How Pressure Converter works
Common pressure units
PSI (pounds per square inch) is used for tyre pressure in the UK and US. Bar is common in European automotive and industrial contexts. kPa (kilopascal) is the SI-preferred unit. 1 bar = 100 kPa ≈ 14.5 PSI.
Standard atmosphere
1 atmosphere (atm) = 101.325 kPa = 1.01325 bar = 14.696 PSI. This is the average air pressure at sea level.
Blood pressure (mmHg)
Blood pressure is measured in millimetres of mercury (mmHg). A reading of 120/80 mmHg is considered normal. 1 mmHg = 133.322 Pa.
Frequently asked questions
What is the tyre pressure in PSI vs bar?
Most UK cars recommend 30–35 PSI (2.07–2.41 bar). The tyre placard on the driver's door shows the manufacturer's recommended pressure in both PSI and bar.
How many PSI in 1 bar?
1 bar = 14.5038 PSI.
What is normal atmospheric pressure in kPa?
Standard atmosphere = 101.325 kPa.
What is a normal blood pressure in kPa?
Normal blood pressure is 120/80 mmHg = 16.0/10.7 kPa. Blood pressure is almost universally expressed in mmHg rather than SI units.
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